Hugo is a mist-free humidifier with a reduced design that works on the basis of evaporation. Water is poured into the top of the unit and absorbed by an antibacterial filter. The water is first purified, filtering out 99.99 per cent of bacteria, before it evaporates. The water vapour is passed through a fine sieve so that humidification of the air takes place without a visible mist. To clean the unit, the bottom cover is simply unscrewed.